Collaborative Research: geophysical evaluation of biogenic gases in peatlands

0510370 0510545 0510004斯莱特激光吸收北部泥炭地通过维管植物的挥发和周期性的沸腾事件排放的生物气体，约占全球每年向大气排放甲烷的7%。这项建议涉及应用探地雷达(GPR)进行实验，以(1)估计泥炭地中储存的生物成因气体的数量，(2)确定泥炭中生物成因气体的空间分布，以及(3)监测生物成因气体向大气的释放。缅因州北部大型泥炭地(EAR-0242353)的资料表明：(1)较高的甲烷和二氧化碳浓度与井间探地雷达数据中的高速/高衰减区以及地面探地雷达数据中的阴影区(反射损失)相关；(2)在该泥炭地采集的+11公里的地面探地雷达数据中，经常观察到阴影区(表示高气体含量)。实验目标是：(1)实验室评估从地表到矿物土壤的泥炭岩心剖面的介电常数与气体含量之间的关系；(2)跨孔探地雷达和地表探地雷达监测实验，辅之以水位、水力传导性和时间域反射仪的测量，以观察生物成因气体向大气释放的速率；(3)地表地质雷达研究，辅以生物成因气体浓度的现场测量，以估计在两个研究得很好的北部泥炭地(东北加勒比沼泽和明尼苏达州阿加西斯湖)中储存的生物成因气体的数量。重要的里程碑包括：(A)从介电常数测量中估计泥炭中的气体含量作为深度的函数的预测方程；(B)对泥炭地气体释放的时间模式和泥炭地的脉动通量的新见解；以及(C)对泥炭地碳库中的游离气含量的新估计，考虑到气体的空间/深度分布。荣誉本科生(HUG)罗格斯-纽瓦克荣誉学院(HC)的研究人员将与一名博士后科学家合作，以获得完成四项主要研究任务所需的研究培训。每个拥抱将完成一项为期一年的高级研究项目，并为一份出版物做出贡献。罗格斯-纽瓦克大学在校园UG多样性方面是美国顶尖的国立大学，这一地位为少数族裔学生提供了HUG机会。罗格斯-纽瓦克大学地球/环境科学专业的学生经常表示对实地考察经验感兴趣。部分实地调查将由参加作为本项目一部分开发的应用地球物理夏季野外夏令营的学生进行。社区外展将通过导游、海报和关于卡里乌沼泽的水文、生态和碳循环的演讲来进行，最近开放的2公里长的奥罗诺木板路为公众提供了进入这个沼泽的便利。最后，与欧洲一位著名的泥炭地学家的合作将吸引国际社会对我们的工作的关注，并提供一个机会，对一个独特的欧洲泥炭沼泽进行比较工作。

0510370 0510545 0510004Slater Glaser ReeveBiogenic gas emission from northern peatlands, by wicking from vascular plants and byepisodic ebullition events, accounts for approximately 7% of the global annual emissionof methane to the atmosphere. This proposal involves experiments to apply groundpenetrating radar (GPR) for (1) estimating the amount of biogenic gas stored in peatlands,(2) determining the spatial distribution of biogenic gas within the peat, and (3)monitoring biogenic gas release to the atmosphere. Data from a large northern peatland inMaine (EAR-0242353) show that (1) higher CH4 and CO2 concentrations correlate withhigh velocity/high attenuation zones in cross-borehole GPR data as well as shadow zones(loss of reflections) in surface GPR data, (2) shadow zones (indicative of high gascontent) are frequently observed in the +11 km of surface GPR data collected in thispeatland. The experimental objectives are: (1) a laboratory evaluation of the relationshipbetween dielectric permittivity and gas content for a profile of peat cores from the surfaceto the mineral soil; (2) a cross-hole GPR and surface GPR monitoring experiment,supported by measurements of water levels, hydraulic conductivity and time domainreflectometry, to observe rates of biogenic gas release to the atmosphere; (3) a surfaceGPR study, supported by in situ measurements of biogenic gas concentration, to estimatethe volume of biogenic gas stored in two well studied northern peatlands (Caribou Bog,ME and Glacial Lake Agassiz, MN). Important milestones include (a) a predictiveequation for gas content estimation in peat as a function of depth from dielectricpermittivity measurements, (b) new insight into the temporal pattern of gas release andebullition flux from peatlands, and (c) new estimates of the free gas content of peatlandcarbon reservoirs accounting for the spatial/depth distribution of the gas.Broader ImpactsThis proposal incorporates educational activities, curriculum development, communityoutreach and international collaboration within an applied research framework. HonorsUnderGraduate (HUG) researchers from the Rutgers-Newark Honors College (HC) willpartner with a postdoctoral scientist to obtain the research training required to completefour of the primary research tasks. Each HUG will complete a yearlong senior project ontheir research and contribute to a publication. The status of Rutgers-Newark as the toprankedNational US University with respect to campus UG diversity facilitates HUGopportunities to minority students. Students in Earth/Environmental Sciences at Rutgers-Newark frequently express interest in fieldwork experiences. Part of the fieldwork will beconducted by students participating in a new class, Summer Field Camp in AppliedGeophysics, developed as part of this project. Community outreach will occur via guidedtours, poster boards and presentations on the hydrology, ecology and carbon cycle inCaribou Bog, facilitated by the recently opened 2 km long Orono boardwalk that nowprovides public access to this bog. Finally, collaboration with a prominent peatlandscientist in Europe will draw international attention to our work and provide anopportunity to conduct comparative work on a unique European peat bog.